This invention relates to a power source wiring system in an electronic circuit device comprising a plurality of electronic circuits. More particularly, the present invention relates to a noise reduction structure for reducing a voltage noise on a power source wiring resulting from a current noise that occurs as a result of operation of an electronic circuit.
In electronic circuit devices comprising a plurality of electronic circuits such as electronic computers, a higher integration density has been sought in recent years with a higher operation speed of individual electronic circuits so as to improve processing speed and obtain reduction in size.
A current noise (an a.c.-like noise current) flows through a power source wiring for feeding power to electronic circuits with the operation of the electronic circuits, and this noise current generates a voltage noise in the power source wiring system. The resulting voltage noise changes the power source voltage of a group of electronic circuits in the vicinity of the electronic circuit in which the current noise occurs, and invites an erroneous operation of these electronic circuits.